From 03855caf93f7332a3f320228ba1a0e7baae8a749 Mon Sep 17 00:00:00 2001
From: Tim Harvey <tharvey@gateworks.com>
Date: Thu, 15 May 2014 12:36:23 -0700
Subject: [PATCH] net: igb: register mii_bus for SerDes w/ external phy

If an i210 is configured for 1000BASE-BX link_mode and has an external phy
specified, then register an mii bus using the external phy address as
a mask.

An i210 hooked to an external standard phy will be configured with a link_mo
of SGMII in which case phy ops will be configured and used internall in the
igb driver for link status. However, in certain cases one might be using a
backplane SerDes connection to something that talks on the mdio bus but is
not a standard phy, such as a switch. In this case by registering an mdio
bus a phy driver can manage the device.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
---
 drivers/net/ethernet/intel/igb/e1000_82575.c |  15 +++
 drivers/net/ethernet/intel/igb/e1000_hw.h    |   7 ++
 drivers/net/ethernet/intel/igb/igb_main.c    | 168 ++++++++++++++++++++++++++-
 3 files changed, 185 insertions(+), 5 deletions(-)

--- a/drivers/net/ethernet/intel/igb/e1000_82575.c
+++ b/drivers/net/ethernet/intel/igb/e1000_82575.c
@@ -624,13 +624,25 @@ static s32 igb_get_invariants_82575(stru
 	switch (link_mode) {
 	case E1000_CTRL_EXT_LINK_MODE_1000BASE_KX:
 		hw->phy.media_type = e1000_media_type_internal_serdes;
+		if (igb_sgmii_uses_mdio_82575(hw)) {
+			u32 mdicnfg = rd32(E1000_MDICNFG);
+			mdicnfg &= E1000_MDICNFG_PHY_MASK;
+			hw->phy.addr = mdicnfg >> E1000_MDICNFG_PHY_SHIFT;
+			hw_dbg("1000BASE_KX w/ external MDIO device at 0x%x\n",
+			       hw->phy.addr);
+		} else {
+			hw_dbg("1000BASE_KX");
+		}
 		break;
 	case E1000_CTRL_EXT_LINK_MODE_SGMII:
 		/* Get phy control interface type set (MDIO vs. I2C)*/
 		if (igb_sgmii_uses_mdio_82575(hw)) {
 			hw->phy.media_type = e1000_media_type_copper;
 			dev_spec->sgmii_active = true;
+			hw_dbg("SGMII with external MDIO PHY");
 			break;
+		} else {
+			hw_dbg("SGMII with external I2C PHY");
 		}
 		/* fall through for I2C based SGMII */
 	case E1000_CTRL_EXT_LINK_MODE_PCIE_SERDES:
@@ -647,8 +659,11 @@ static s32 igb_get_invariants_82575(stru
 				hw->phy.media_type = e1000_media_type_copper;
 				dev_spec->sgmii_active = true;
 			}
+			hw_dbg("SERDES with external SFP");
 
 			break;
+		} else {
+			hw_dbg("SERDES");
 		}
 
 		/* do not change link mode for 100BaseFX */
--- a/drivers/net/ethernet/intel/igb/e1000_hw.h
+++ b/drivers/net/ethernet/intel/igb/e1000_hw.h
@@ -27,6 +27,7 @@
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/netdevice.h>
+#include <linux/phy.h>
 
 #include "e1000_regs.h"
 #include "e1000_defines.h"
@@ -543,6 +544,12 @@ struct e1000_hw {
 	struct e1000_mbx_info mbx;
 	struct e1000_host_mng_dhcp_cookie mng_cookie;
 
+#ifdef CONFIG_PHYLIB
+	/* Phylib and MDIO interface */
+	struct mii_bus *mii_bus;
+	struct phy_device *phy_dev;
+	phy_interface_t phy_interface;
+#endif
 	union {
 		struct e1000_dev_spec_82575	_82575;
 	} dev_spec;
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -41,6 +41,7 @@
 #include <linux/if_vlan.h>
 #include <linux/pci.h>
 #include <linux/pci-aspm.h>
+#include <linux/phy.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/ip.h>
@@ -2217,6 +2218,126 @@ static s32 igb_init_i2c(struct igb_adapt
 	return status;
 }
 
+
+#ifdef CONFIG_PHYLIB
+/*
+ * MMIO/PHYdev support
+ */
+
+static int igb_enet_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
+{
+	struct e1000_hw *hw = bus->priv;
+	u16 out;
+	int err;
+
+	err = igb_read_reg_gs40g(hw, mii_id, regnum, &out);
+	if (err)
+		return err;
+	return out;
+}
+
+static int igb_enet_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
+                               u16 val)
+{
+	struct e1000_hw *hw = bus->priv;
+
+	return igb_write_reg_gs40g(hw, mii_id, regnum, val);
+}
+
+static int igb_enet_mdio_reset(struct mii_bus *bus)
+{
+	udelay(300);
+	return 0;
+}
+
+static void igb_enet_mii_link(struct net_device *netdev)
+{
+}
+
+/* Probe the mdio bus for phys and connect them */
+static int igb_enet_mii_probe(struct net_device *netdev)
+{
+	struct igb_adapter *adapter = netdev_priv(netdev);
+	struct e1000_hw *hw = &adapter->hw;
+	struct phy_device *phy_dev = NULL;
+	int phy_id;
+
+	/* check for attached phy */
+	for (phy_id = 0; (phy_id < PHY_MAX_ADDR); phy_id++) {
+		if (hw->mii_bus->phy_map[phy_id]) {
+			phy_dev = hw->mii_bus->phy_map[phy_id];
+			break;
+		}
+	}
+	if (!phy_dev) {
+		netdev_err(netdev, "no PHY found\n");
+		return -ENODEV;
+	}
+
+	hw->phy_interface = PHY_INTERFACE_MODE_RGMII;
+	phy_dev = phy_connect(netdev, dev_name(&phy_dev->dev),
+			      igb_enet_mii_link, hw->phy_interface);
+	if (IS_ERR(phy_dev)) {
+		netdev_err(netdev, "could not attach to PHY\n");
+		return PTR_ERR(phy_dev);
+	}
+
+	hw->phy_dev = phy_dev;
+	netdev_info(netdev, "igb PHY driver [%s] (mii_bus:phy_addr=%s)\n",
+		hw->phy_dev->drv->name, dev_name(&hw->phy_dev->dev));
+
+	return 0;
+}
+
+/* Create and register mdio bus */
+static int igb_enet_mii_init(struct pci_dev *pdev)
+{
+	struct mii_bus *mii_bus;
+	struct net_device *netdev = pci_get_drvdata(pdev);
+	struct igb_adapter *adapter = netdev_priv(netdev);
+	struct e1000_hw *hw = &adapter->hw;
+	int err;
+
+	mii_bus = mdiobus_alloc();
+	if (mii_bus == NULL) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+
+	mii_bus->name = "igb_enet_mii_bus";
+	mii_bus->read = igb_enet_mdio_read;
+	mii_bus->write = igb_enet_mdio_write;
+	mii_bus->reset = igb_enet_mdio_reset;
+	snprintf(mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
+		 pci_name(pdev), hw->device_id + 1);
+	mii_bus->priv = hw;
+	mii_bus->parent = &pdev->dev;
+	mii_bus->phy_mask = ~(1 << hw->phy.addr);
+
+	err = mdiobus_register(mii_bus);
+	if (err) {
+		printk(KERN_ERR "failed to register mii_bus: %d\n", err);
+		goto err_out_free_mdiobus;
+	}
+	hw->mii_bus = mii_bus;
+
+	return 0;
+
+err_out_free_mdiobus:
+	mdiobus_free(mii_bus);
+err_out:
+	return err;
+}
+
+static void igb_enet_mii_remove(struct e1000_hw *hw)
+{
+	if (hw->mii_bus) {
+		mdiobus_unregister(hw->mii_bus);
+		mdiobus_free(hw->mii_bus);
+	}
+}
+#endif /* CONFIG_PHYLIB */
+
 /**
  *  igb_probe - Device Initialization Routine
  *  @pdev: PCI device information struct
@@ -2641,6 +2762,13 @@ static int igb_probe(struct pci_dev *pde
 		}
 	}
 	pm_runtime_put_noidle(&pdev->dev);
+
+#ifdef CONFIG_PHYLIB
+	/* create and register the mdio bus if using ext phy */
+	if (rd32(E1000_MDICNFG) & E1000_MDICNFG_EXT_MDIO)
+		igb_enet_mii_init(pdev);
+#endif
+
 	return 0;
 
 err_register:
@@ -2788,6 +2916,10 @@ static void igb_remove(struct pci_dev *p
 	struct e1000_hw *hw = &adapter->hw;
 
 	pm_runtime_get_noresume(&pdev->dev);
+#ifdef CONFIG_PHYLIB
+	if (rd32(E1000_MDICNFG) & E1000_MDICNFG_EXT_MDIO)
+		igb_enet_mii_remove(hw);
+#endif
 #ifdef CONFIG_IGB_HWMON
 	igb_sysfs_exit(adapter);
 #endif
@@ -3113,6 +3245,12 @@ static int __igb_open(struct net_device
 	if (!resuming)
 		pm_runtime_put(&pdev->dev);
 
+#ifdef CONFIG_PHYLIB
+	/* Probe and connect to PHY if using ext phy */
+	if (rd32(E1000_MDICNFG) & E1000_MDICNFG_EXT_MDIO)
+		igb_enet_mii_probe(netdev);
+#endif
+
 	/* start the watchdog. */
 	hw->mac.get_link_status = 1;
 	schedule_work(&adapter->watchdog_task);
@@ -7106,21 +7244,41 @@ void igb_alloc_rx_buffers(struct igb_rin
 static int igb_mii_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
 {
 	struct igb_adapter *adapter = netdev_priv(netdev);
+	struct e1000_hw *hw = &adapter->hw;
 	struct mii_ioctl_data *data = if_mii(ifr);
 
-	if (adapter->hw.phy.media_type != e1000_media_type_copper)
+	if (adapter->hw.phy.media_type != e1000_media_type_copper &&
+	    !(rd32(E1000_MDICNFG) & E1000_MDICNFG_EXT_MDIO))
 		return -EOPNOTSUPP;
 
 	switch (cmd) {
 	case SIOCGMIIPHY:
-		data->phy_id = adapter->hw.phy.addr;
+		data->phy_id = hw->phy.addr;
 		break;
 	case SIOCGMIIREG:
-		if (igb_read_phy_reg(&adapter->hw, data->reg_num & 0x1F,
-				     &data->val_out))
-			return -EIO;
+		if (hw->mac.type == e1000_i210 || hw->mac.type == e1000_i211) {
+			if (igb_read_reg_gs40g(&adapter->hw, data->phy_id,
+					       data->reg_num & 0x1F,
+			                       &data->val_out))
+				return -EIO;
+		} else {
+			if (igb_read_phy_reg(&adapter->hw, data->reg_num & 0x1F,
+			                     &data->val_out))
+				return -EIO;
+		}
 		break;
 	case SIOCSMIIREG:
+		if (hw->mac.type == e1000_i210 || hw->mac.type == e1000_i211) {
+			if (igb_write_reg_gs40g(hw, data->phy_id,
+					        data->reg_num & 0x1F,
+					        data->val_in))
+				return -EIO;
+		} else {
+			if (igb_write_phy_reg(hw, data->reg_num & 0x1F,
+					      data->val_in))
+				return -EIO;
+		}
+		break;
 	default:
 		return -EOPNOTSUPP;
 	}
